Channel Estimation in Wireless Networks

1. A method for wireless communications, comprising: receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a Doppler estimation of the UE, and a configuration of subframes prior to the current subframe, wherein the Doppler estimation is adjusted based at least in part on a number of subframes prior to the current subframe in which transmission of downlink reference signals is limited or non-existent.

2. The method of claim 1 , wherein subframes prior to the current subframe comprise subframes in which transmission of downlink reference signals is limited or non-existent.

3. The method of claim 2 , wherein the performing the channel estimation comprises: using a zero coefficient for reference signal symbols in the subframes in which transmission of the downlink reference signals is limited or non-existent.

4. The method of claim 1 , wherein if the adjusted Doppler estimation of the UE is less than a threshold value, the channel estimation is performed based at least in part on reference signals received in one or more previous downlink subframes.

5. The method of claim 1 , wherein if the adjusted Doppler estimation of the UE is greater than a threshold value, the channel estimation is performed based on reference signals received in the current subframe only.

6. A method for wireless communications, comprising: receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein the channel estimation is based at least in part on reference signals received in one or more previous downlink subframes only if the UE is operating in a high current mode in which continuity of phase between subframes is maintained.

7. A method for wireless communications, comprising: receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein the performing the channel estimation comprises: using a group delay to skip at least a first reference signal symbol in the current subframe.

8. An apparatus for wireless communications, comprising: means for receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and means for performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a Doppler estimation of the UE, and a configuration of subframes prior to the current subframe, wherein the Doppler estimation is adjusted based at least in part on a number of subframes prior to the current subframe in which transmission of downlink reference signals is limited or non-existent.

9. The apparatus of claim 8 , wherein subframes prior to the current subframe comprise subframes in which transmission of downlink reference signals is limited or non-existent.

10. The apparatus of claim 9 , wherein the means for performing the channel estimation comprises: means for using a zero coefficient for reference signal symbols in the subframes in which transmission of the downlink reference signals is limited or non-existent.

11. The apparatus of claim 8 , wherein if the adjusted Doppler estimation of the UE is less than a threshold value, the channel estimation is performed based at least in part on reference signals received in one or more previous downlink subframes.

12. The apparatus of claim 8 , wherein if the adjusted Doppler estimation of the UE is greater than a threshold value, the channel estimation is performed based on reference signals received in the current subframe only.

13. An apparatus for wireless communications, comprising: means for receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and means for performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein the channel estimation is based at least in part on reference signals received in one or more previous downlink subframes only if the UE is operating in a high current mode in which continuity of phase between subframes is maintained.

14. An apparatus for wireless communications, comprising: means for receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and means for performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein the means for performing the channel estimation comprises: means for using a group delay to skip at least a first reference signal symbol in the current subframe.

15. An apparatus for wireless communications, comprising: at least one processor configured to: receive, at a user equipment (UE), reference signals from a base station in a current subframe; and perform channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a Doppler estimation of the UE, and a configuration of subframes prior to the current subframe, wherein the Doppler estimation is adjusted based at least in part on a number of subframes prior to the current subframe in which transmission of downlink reference signals is limited or non-existent; and a memory coupled to the at least one processor.

16. The apparatus of claim 15 , wherein subframes prior to the current subframe comprise subframes in which transmission of downlink reference signals is limited or non-existent.

17. The apparatus of claim 16 , wherein performing the channel estimation comprises: using a zero coefficient for reference signal symbols in the subframes in which transmission of the downlink reference signals is limited or non-existent.

18. The apparatus of claim 15 , wherein if the adjusted Doppler estimation of the UE is less than a threshold value, the channel estimation is performed based at least in part on reference signals received in one or more previous downlink subframes.

19. The apparatus of claim 15 , wherein if the adjusted Doppler estimation of the UE is greater than a threshold value, the channel estimation is performed based on reference signals received in the current subframe only.

20. An apparatus for wireless communications, comprising: at least one processor configured to: receive, at a user equipment (UE), reference signals from a base station in a current subframe; and perform channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein the channel estimation is based at least in part on reference signals received in one or more previous downlink subframes only if the UE is operating in a high current mode in which continuity of phase between subframes is maintained; and a memory coupled to the at least one processor.

21. An apparatus for wireless communications, comprising: at least one processor configured to: receive, at a user equipment (UE), reference signals from a base station in a current subframe; and perform channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein performing channel estimation comprises: using a group delay to skip at least a first reference signal symbol in the current subframe; and a memory coupled to the at least one processor.

22. A computer-program product for wireless communications, the computer-program product comprising: a non-transitory computer-readable medium having code for: receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a Doppler estimation of the UE, and a configuration of subframes prior to the current subframe, wherein the Doppler estimation is adjusted based at least in part on a number of subframes prior to the current subframe in which transmission of downlink reference signals is limited or non-existent.

23. The computer-program product of claim 22 , wherein subframes prior to the current subframe comprise subframes in which transmission of downlink reference signals is limited or non-existent.

24. The computer-program product of claim 23 , wherein the code for performing the channel estimation comprises: code for using a zero coefficient for reference signal symbols in the subframes in which transmission of the downlink reference signals is limited or non-existent.

25. The computer-program product of claim 22 , wherein if the adjusted Doppler estimation of the UE is less than a threshold value, the channel estimation is performed based at least in part on reference signals received in one or more previous downlink subframes.

26. The computer-program product of claim 22 , wherein if the adjusted Doppler estimation of the UE is greater than a threshold value, the channel estimation is performed based on reference signals received in the current subframe only.

27. A computer-program product for wireless communications, the computer-program product comprising: a non-transitory computer-readable medium having code for: receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein the channel estimation is based at least in part on reference signals received in one or more previous downlink subframes only if the UE is operating in a high current mode in which continuity of phase between subframes is maintained.

28. A computer-program product for wireless communications, the computer-program product comprising: a non-transitory computer-readable medium having code for: receiving, at a user equipment (UE), reference signals from a base station in a current subframe; and performing channel estimation, wherein the channel estimation is based at least in part on the reference signals received in the current subframe, a mobility characteristic of the UE, and a configuration of subframes prior to the current subframe, wherein the code for performing the channel estimation comprises: code for using a group delay to skip at least a first reference signal symbol in the current subframe.